110 NEW INVERTEBRATA FROM 



though a similar and larger genus, Proboscidactyla, is 

 recorded from certain places. 



I found at the island of Santa Cruz a medusa which was 

 at first mistaken for a young Proboscidactyla, but which 

 turns out on closer study to have marked differences from 

 this genus. 



The bell is semiovate, with a slight constriction in its 

 external outlines oil a level with the base of the proboscis. 

 Ovaries are four in number, arranged at the base of a four- 

 parted stomach. Gastro-vessels four, subdivided before 

 their union with the circular vessel into four branches. Op- 

 posite the junction of each branch with the circular vessel, 

 there arises a simple tentacle. The margin of the bell bears 

 twenty tentacles. Each tentacle is colorless, and at its base 

 or bulb bears a bright colored, reddish ocellus. 



Each tube of the radial system before junction with the 

 marginal is first divided into three divisions, two of which 

 subdivide into two more. The median of the three origi- 

 nal divisions extends directly to the bell margin. 1 



On the outer surface of the bell, between each pair of 

 tentacles, there is a cluster of cells, 2 connected with the 

 rim of the bell by means of a simple band, which is nar- 

 row and inconspicuous. The cells are similar to structures 

 in an identical position in Gemmaria, and correspond to 

 like organs in our east coast Willia with four tubes, before 

 the lateral branches have formed. In the Atlantic species, 

 W. ornata, these structures are evidently embryonic, and 

 the same may be true in the Pacific species of this genus. 



The special function of these cells and of this band is 

 not clear to me. They may possibly be comparable with 

 the embryonic tentacles of the larval Glossocodon. 



J In Willia from the Atlantic each tube is divided into four subdivisions, before 

 junction with the tube of the bell margin. In W. stdlata there are six of these 

 tubes before division. 



2 I did not detect the coiled thread in the interior of these cells. 



